Primer and method of manufactureing and loading the same



Jan. 2, 1945. w. P. HILL 2,366,333

PRIMER AND METHOD OF MANUFACTURING AND LOADING THE SAME Filed July 12, 1943 INVENTOR.

' WALTER P. HILL ATTORNEYS Patented Jan. 2, 1945 UNITED STATES ()FFICE.

PRIMER AND-METHOD OFMA'NUFAUTUR- ING AND LOADING 'THE SAME Walter P. Hill, Detroit, Micha,,assignor to Gain? met and' Hcla Consolidated.v Copper Company, Calumet, Mich, a corporation ofIMichi'ga'n dpplicati'onluly'm, 1943,8erial1Nb. 494,387

4 Claims;

This invention relates to primersi'for use in projectiles and'to'the method of manufacturing andiloadingthe same.

One" oithe principal objects of thisinvention is to.zprovide'an-improved primer, the body and fire? tube of which may be producedfrom tubing, thereby simplifying'the construction and reducing'the number of operations required to produce and assemble theis'a'me.

Another primary object of this invention is'to provide a simplified method. of loading the primer whereby. the assembly of the'fire tube with the.

primer'b'ody is greatly facilitated.

Many other objects andiadvanta'ges-of this-invention will become moreapparent as thisdescription proceeds, especially when considered'in connection with the accompanying drawing, wherein:

Figure 1 is a sectional elevational view of a primer constructed in accordance with this inve-ntion.

Figure 2 is a sectional elevational view showing the method of closing one end of the fire tube and, .of the primer body.

Figure 3 is a sectional view showing the base and fire tube assembled.

Figure 4 is a sectional view of the primer body loaded and ready for assembly with the fire tube and base, and

Figure 5 is a sectional View showing the method of assembling the fire tube with the primer body.

Referring first to Figure 1, it will be noted that the primer comprises a body H! having an integral closed end II and an open opposite end through which the body is charged with a powder or other compound, which end is closed by a base 12. The base 12 is provided with a reduced externally threaded portion [3, with an externally threaded portion IA of larger diameter forming an annular shoulder I5 and with a head It.

Reference character I8 indicates a fire tube having a closed end I 9. Th open end of the fire tube 18 is externally threaded to engage a tapped bore 20 in the base l2.

The primer body I I! is provided with a plurality of holes or apertures 2! which permit the charge in the primer, when the latter is set off, to escape to ignite the propelling charge in the casing of the projectile.

The fire tube is likewise provided with a plurality of holes or apertures 22 which permit the charge in the fire tube, when the same is set off, to escape and ignite the charge in the main primer body.

Both the primer body and the fire tube l8 aremade-of' tubing, preferably drawn seamless tubing. Thus both of these elements of the primer may bernade of any desired lengthby cutting the same off lengthsbft'ubing;

It will be noted that the primer bod in has an integral'closed end H and=that the fire tube it has an integral closed end ill: The integral closedend ll eliminates-the necessity of using a separate plug to'close the same as has heretofore been'the'practioe. In accordance with prior practices, such plugs were produced on a screw machine and'the'en-d 'of 'theprimer body had to be drilled, counterbored, and tapped'to receive the plug. Also, the plug had to be'a'ssembled with the end ofthe' primer body and thereafter the counterb'ored portion was crimped over to hold the plug in place. These operations-are eliminated by the use-ofan integralclosed end as herein disclosed.

The fire tube is also providedwith an integral closed end IQ'which is 'animprovement over prior methodswherein the end of the fire tube was closed by fiattening'the same. i

The closed ends III I and 1 I9 areJpreferably, although not necessarily; accomplished by the method and means described in my Patent No. 2,313,474, dated March 9, 1943, by means of the tool illustrated in Figures 8, 9 and 10 of said patent.

As shown in Figure 2 heretof this tool 23 is provided with a spindle 24 so that the same may be attached to a rotatable member for rotating the tool. The tool is provided with an opening 25 of sufiicient diameter to receive the end of the tube from which either the primer body or fire tube is made, as the tube is forced into engagement with the tool and into the semi-spherical shaped cavity 26 formed therein. The end of the opening 25 adjacent the cavity 26 is preferably, although not necessarily, formed with a continuous annular portion 2'! which gradually decreases in cross-section in the direction of the cavity and which exerts a reducing pressure-continuously around the entire circumference of the tube to progressively heat the same to a plastic or easily workable condition. The cavity 26 is provided with a relief portion 28 which permits successive portions of the stock to deform thereinto during the reducing operation, and prevent seizure between the tube and tool due to thermal expansion of the tube.

' As stated, the tool and tube are relatively rotated and moved axially toward one another. This results in a closing-in of the tube as shown, until the end is completely closed. By continued relative movement of the tube and tool toward one another, the tube wall at the end may be thickened as illustrated at H and l9.

Before filling the fire tube l8 with powder, it is customary to insert therein a sleeve or cylindrical envelope of paper. The fire tube after being charged or filled with powder (not shown) is assembled with the base l2 by screwing the threaded end of the fire tube into the tapped bore 20.

In Figure 4 the main primer body I0 is shown as charged with a predetermined amount of powder or other compound P, sufiicient to fill the primer body to the desired extent when the fire tube is in place. The customary sleeve or cylindrical envelope of paper is not shown. The next step is to assemble the fire tube and base with the main primer body. Inasmuch as the primer body is substantially filled with powder, some resistance is encountered in inserting the fire tube l8 into the primer body andthrough the charge of powder therein. To simplify and facilitate this assembly operation, I provide a stopper 28 for the powder in the form of a disc of paper or the like. This stopper 29 is inserted into the open end of the primer body ED in engagement with the tapped portion l'! and is provided with an aperture 33 just large enough to receive thefire tube IS. The end of the fire tube I8 is then inserted into the aperture 30 and the primer parts are turned into an upright position as shown in Figure 5. Therefore, as the fire tube is shoved into the primer body, the powder falls downwardly around the fire tube ofiering little or no resistance to the entrance of the fire tube and during this operation the stopper, of course, prevents the powder from spilling out of the primer body. As soon as the reduced portion 13 of the base comes into engagement with the stopper 29, it is forced into the primer body and dislodged from the threads or tapped portion l1 whereupon the reduced portion 13 of the base may be screwed home into the tapped portion 11. The dislodged stopper 29 is shown in its dislodged position in Figure 1.

What I claim as my invention is:

1. The method of loading and assembling primers of the class described which consists in introducing a charge of powder into the primer body through the open end thereof, placing an apertured stopper in said open end, inserting the end of a fire tube through said aperture, and completing the insertion with the parts in a position wherein the charge of powder will fiow by gravity around said fire tube permitting.

ready insertion thereof.

12. The method of loading primers having a primer body open at one end and a fire tube to be inserted therein through said open end which comprises, introducing a charge of powder into the primer body through the open end thereof,

' placing an apertured stopper in said open end,

inserting the end of the fire tube through said aperture, and continuing its inward movement while in a position for the charge to flow around the same by gravity.

3. The method of loading primers having a primer body charged with powder and a fire tube adapted to be inserted therein through an open end thereof which consists in inserting an apertured stopper in said open end, inserting the fire tube into the aperture of the stopper, inverting the primer body and pressing the fire tube into said primer body while in position wherein the powder will flow by gravity around said tube.

4. The method of loading and assembling primers having a primer body provided with a threaded open end, and a fire tube adapted to be inserted into said body with a base adapted to be engaged with said threaded end, comprising, introducing a charge of powder into the primer body through its open end, placing an apertured stopper in said threaded end, inserting the end of the fire tube into said aperture.

and completing the insertion with said stoppered end downward, said stopper being dislodged when said base engages said threaded end.

WALTER P. HILL. 

